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Edmunds PJ. Coral recruitment: patterns and processes determining the dynamics of coral populations. Biol Rev Camb Philos Soc 2023; 98:1862-1886. [PMID: 37340617 DOI: 10.1111/brv.12987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/30/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023]
Abstract
Coral recruitment describes the addition of new individuals to populations, and it is one of the most fundamental demographic processes contributing to population size. As many coral reefs around the world have experienced large declines in coral cover and abundance, there has been great interest in understanding the factors causing coral recruitment to vary and the conditions under which it can support community resilience. While progress in these areas is being facilitated by technological and scientific advances, one of the best tools to quantify recruitment remains the humble settlement tile, variants of which have been in use for over a century. Here I review the biology and ecology of coral recruits and the recruitment process, largely as resolved through the use of settlement tiles, by: (i) defining how the terms 'recruit' and 'recruitment' have been used, and explaining why loose terminology has impeded scientific advancement; (ii) describing how coral recruitment is measured and why settlement tiles have value for this purpose; (iii) summarizing previous efforts to review quantitative analyses of coral recruitment; (iv) describing advances from hypothesis-driven studies in determining how refuges, seawater flow, and grazers can modulate coral recruitment; (v) reviewing the biology of small corals (i.e. recruits) to understand better how they respond to environmental conditions; and (vi) updating a quantitative compilation of coral recruitment studies extending from 1974 to present, thus revealing long-term global declines in density of recruits, juxtaposed with apparent resilience to coral bleaching. Finally, I review future directions in the study of coral recruitment, and highlight the need to expand studies to deliver taxonomic resolution, and explain why time series of settlement tile deployments are likely to remain pivotal in quantifying coral recruitment.
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Affiliation(s)
- Peter J Edmunds
- Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA, 91330-8303, USA
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Tebbett SB, Schlaefer JA, Bowden CL, Collins WP, Hemingson CR, Ling SD, Morais J, Morais RA, Siqueira AC, Streit RP, Swan S, Bellwood DR. Bio-physical determinants of sediment accumulation on an offshore coral reef: A snapshot study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165188. [PMID: 37385494 DOI: 10.1016/j.scitotenv.2023.165188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/15/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Sediments are found on all coral reefs around the globe. However, the amount of sediment in different reservoirs, and the rates at which sediments move between reservoirs, can shape the biological functioning of coral reefs. Unfortunately, relatively few studies have examined reef sediment dynamics, and associated bio-physical drivers, simultaneously over matching spatial and temporal scales. This has led to a partial understanding of how sediments and living reef systems are connected, especially on clear-water offshore reefs. To address this problem, four sediment reservoirs/sedimentary processes and three bio-physical drivers were quantified across seven different reef habitats/depths at Lizard Island, an exposed mid-shelf reef on the Great Barrier Reef. Even in this clear-water reef location a substantial load of suspended sediment passed over the reef; a load theoretically capable of replacing the entire standing stock of on-reef turf sediments in just 8 h. However, quantification of actual sediment deposition suggested that just 2 % of this passing sediment settled on the reef. The data also revealed marked spatial incongruence in sediment deposition (sediment trap data) and accumulation (TurfPod data) across the reef profile, with the flat and back reef emerging as key areas of both deposition and accumulation. By contrast, the shallow windward reef crest was an area of deposition but had a limited capacity for sediment accumulation. These cross-reef patterns related to wave energy and reef geomorphology, with low sediment accumulation on the ecologically important reef crest aligning with substantial wave energy. These findings reveal a disconnect between patterns of sediment deposition and accumulation on the benthos, with the 'post-settlement' fate of sediments dependent on local hydrodynamic conditions. From an ecological perspective, the data suggests key contextual constraints (wave energy and reef geomorphology) may predispose some reefs or reef areas to high-load turf sediment regimes.
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Affiliation(s)
- Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia.
| | - Jodie A Schlaefer
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Commonwealth Scientific and Industrial Research Organisation (CSIRO), Environment, Townsville, Queensland, 4811, Australia
| | - Casey L Bowden
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - William P Collins
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Christopher R Hemingson
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Department of Marine Science, The University of Texas at Austin, Marine Science Institute, Port Aransas, TX, USA
| | - Scott D Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7001, Australia
| | - Juliano Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Renato A Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Paris Sciences et Lettres Université, École Pratique des Hautes Études, EPHE-UPVD-CNRS, USR 3278 CRIOBE, University of Perpignan, Perpignan, France
| | - Alexandre C Siqueira
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Robert P Streit
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Sam Swan
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
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Randall CJ, Giuliano C, Allen K, Bickel A, Miller M, Negri AP. Site mediates performance in a coral seeding trial. Restor Ecol 2022. [DOI: 10.1111/rec.13745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Katie Allen
- Australian Institute of Marine Science Townsville QLD Australia
| | | | | | - Andrew P. Negri
- Australian Institute of Marine Science Townsville QLD Australia
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